Sulfur Isotopic Fractionation of Carbonyl Sulfide during Degradation by Soil Bacteria.
Sulfur Isotopic Fractionation of Carbonyl Sulfide during Degradation by Soil Bacteria.
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DOI：
10.1021/acs.est.5b05325
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发表时间：
2016-03
影响因子：
11.4
通讯作者：
Kazuki Kamezaki;S. Hattori;T. Ogawa;S. Toyoda;H. Kato;Y. Katayama;N. Yoshida
中科院分区：
文献类型：
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作者：
Kazuki Kamezaki;S. Hattori;T. Ogawa;S. Toyoda;H. Kato;Y. Katayama;N. Yoshida
通过室内培养实验，研究了土壤细菌对气相羰基硫（OCS）的降解作用，测定了OCS的硫同位素分馏常数（34 ε）。使用从自然土壤环境中分离的属于分枝杆菌属、Williamsia属和贪铜菌属的菌株进行孵育实验。分枝杆菌的ε值分别为-3.67 ± 0.33‰、-3.99 ± 0.19‰、-3.57 ± 0.22‰和-3.56 ± 0.23‰。菌株THI 401、THI 402、THI 404和THI 405; Williamsia sp.菌株THI 410为-3.74 ± 0.29‰;菌株THI 414和THI 415。虽然同一属的菌株的OCS降解速率除以细胞数（细胞比活性）不同，但同一属的菌株的（34）ε值没有显著差异。尽管检测的细菌种类数量有限，但我们的结果表明，OCS细菌降解的ε值不取决于细胞特异性活性，而是取决于属水平的生物学差异，这表明ε值取决于酶和/或膜特性。以我们的（34）ε值为代表的细菌OCS降解，OCS的δ（34）S值的预期大气变化范围为0.5‰至0.9‰，基于先前报道的Mt.日本富士。因此，对流层观测OCS的δ（34）S值与OCS细菌降解的（34）ε值相结合，可以潜在地用于研究土壤作为OCS汇。
We performed laboratory incubation experiments on the degradation of gaseous phase carbonyl sulfide (OCS) by soil bacteria to determine its sulfur isotopic fractionation constants ((34)ε). Incubation experiments were conducted using strains belonging to the genera Mycobacterium, Williamsia, and Cupriavidus isolated from natural soil environments. The (34)ε values determined were -3.67 ± 0.33‰, -3.99 ± 0.19‰, -3.57 ± 0.22‰, and -3.56 ± 0.23‰ for Mycobacterium spp. strains THI401, THI402, THI404, and THI405; -3.74 ± 0.29‰ for Williamsia sp. strain THI410; and -2.09 ± 0.07‰ and -2.38 ± 0.35‰ for Cupriavidus spp. strains THI414 and THI415. Although OCS degradation rates divided by cell numbers (cell-specific activity) were different among strains of the same genus, the (34)ε values for same genus showed no significant differences. Even though the numbers of bacterial species examined were limited, our results suggest that (34)ε values for OCS bacterial degradation depend not on cell-specific activities, but on genus-level biological differences, suggesting that (34)ε values are dependent on enzymatic and/or membrane properties. Taking our (34)ε values as representative for bacterial OCS degradation, the expected atmospheric changes in δ(34)S values of OCS range from 0.5‰ to 0.9‰, based on previously reported decreases in OCS concentrations at Mt. Fuji, Japan. Consequently, tropospheric observation of δ(34)S values for OCS coupled with (34)ε values for OCS bacterial degradation can potentially be used to investigate soil as an OCS sink.